Someone came in my office today with a similiar article in "Kitplanes" magazine for May 1999. That article addressed this issue from affect on pilots but mentioned many of the same aspects as the following article.
Thought Blue Himlayan may enjoy this article:
CMEs - If The Sun Spits,
The Earth Could Fry
By David Appell
www.newscientist.com
3-1-99
If the Sun spits, the Earth fries. Humankind is ill-prepared for the furious
climax of the next solar cycle.
Batten down the hatches, there's a storm coming. Some time in the next 18
months, the Sun will turn from a relatively placid ball of hot ionised gases into
a raging tempest of plasma, spitting fireballs out into the Solar System like an
angry god. Woe betide any planet that gets in its way.
Should one of those plasma storms hit Earth, the impact could be devastating.
Each fireball--known as a coronal mass ejection--is a giant maelstrom of
ionised gases at temperatures of well over a million degrees. But the
temperature is the least of Earth's worries. The plasma will tear through the
Earth's magnetic field like wind through grass. These wildly fluctuating fields
can knock out power supplies, and charged particles from the plasma can fry
the electronic components inside telecommunications satellites, bringing down
communications networks over vast areas. A few scientists and engineers are
preparing for the worst while others, strangely, have chosen to ignore the
problem. The wary few are racing to put in place measures to protect power
grids and telecommunications networks, and have launched sentinels that sit in
space between the Earth and the Sun watching for storm signs. In addition,
they are developing complex computer models to predict which parts of the
Earth might be affected. Others, fearing the worst, are waiting to see what
happens to the giant communications networks that have grown up since the
last big solar storm 10 years ago.
Scientists have been watching the changing nature of the Sun for over 200
years and have witnessed these solar rages every eleven years or so. This will
be the 23rd cycle on record and researchers believe it will be every bit as bad
as the last. Six million people in the Canadian province of Quebec can testify to
its effects.
The storm struck in the early hours of 13 March 1989. It was not a good night
to lose power. The temperature had dropped to -15 0C and furnaces went
quiet as six million Canadians lost heat and light. After the winter sunrise,
subways sat still for lack of power, traffic lights hung dark and petrol pumps
refused to deliver.
Later in the day, when public officials called for an explanation, engineers at
Hydro-Quebec, the region's power generating company, had begun to suspect
an unusual culprit. Four days earlier, a giant bubble of plasma had burst from
the surface of Sun. That morning it had hit the Earth, wreaking havoc.
Rapidly changing magnetic fields generate currents in any conductors within
reach. This is how a dynamo works--except that the magnetic field remains still
in these devices while the conducting wires move through it. When a magnetic
storm hits the Earth, any networks of conductors that stretch over the same
scale as the magnetic fluctuations act like giant dynamos. Hydro-Quebec's
transmission lines stretch for over 1000 kilometres. Power lines, telephone
lines and even railway lines are all potential conduits for "geomagnetically
induced currents" (GICs) of hundreds of amperes.
Power companies are vulnerable because their power lines guide the GICs
towards sensitive components such as transformers at power stations and
substations. A transformer changes a high voltage supply of alternating current
into a low voltage supply or vice versa. It consists of a giant doughnut of iron
with two sets of windings on each side of the structure. The voltage in one set
of windings induces a magnetic field in the iron core, which in turn induces a
voltage in the second set of windings. The ratio of the number of windings in
the two coils determines the change in voltage.
High-performance transformers are delicate machines. They are designed to
cope with voltages within a specific range of amplitudes and frequencies.
Outside these bounds, the transformer behaves unpredictably.
The trouble with GICs is that the voltages associated with them change this
delicate balance. In particular, they set up voltages at harmonic frequencies to
the ordinary load. These frequencies are transformed but in a way that can
rapidly spiral out of control. The result is wildly fluctuating voltages called
voltage asymmetries. If the power is not shut down, these can create enough
heat to damage the iron core beyond repair. Worse, these fluctuations pass
rapidly through the network so that neighbouring transformers also become
affected. Within seconds an entire network can collapse as one transformer
after another fails.
Exactly this happened to Hydro-Quebec's power system that fateful morning.
"Voltage regulations need to be within 5 to 10 per cent of a nominal value. If
you fall outside that, you generally see a system collapse and the start of a
domino effect," says John Kappenman, an expert in the effects of geomagnetic
storms at the Metatech Corporation, based in Goleta, California.
Many other electricity utilities around the world also suffered the effects of
GICs that morning. Further south, the iron core of a transformer at a New
Jersey power station burnt out and had to be replaced at a cost of several
million dollars. Later, researchers at the Oak Ridge National Laboratory in
Tennessee predicted the potential effects of a geomagnetic storm only slightly
more severe than the one in 1989. They concluded that the ensuing blackouts
and chaos could cost the US economy up to $6 billion dollars in lost business.
Astronomers are forecasting storms just as big as those in 1989 for the next
solar maximum, if not bigger. As the Sun passes through its 11-year cycle,
solar astronomers measure the activity on its surface by counting the number
of sunspots and the number of groups of sunspots they can see during a
predetermined period, usually a month or a year. Together, these numbers
allow them to calculate an index of solar activity known as the International
Sunspot Number. During the solar minimum, the sunspot number can be as
low as 10. In July 1989, during the last solar maximum, it peaked at 159. And
in March 1958, it reached 201, the highest level ever recorded (see
-- Texan (late@ranch.com), April 09, 1999